Fire extinguishing foam concentrate

ABSTRACT

Fire extinguishing foam concentrate, compatible with sea water, comprises as active ingredient at least 10% by weight of a water soluble, surface active organo-silicon compound.

tlite States Patent Rossmy et a1.

[ Dec. 30, 1975 FIRE EXTINGUISHING FQAM CONCENTRATE Inventors: Gerd Rossmy, Essen-Werden; Giitz Koerner, Essen, both of Germany Assignee: Th. Goldschmidt AG, Germany Filed: Mar. 19, 1973 Appl. No.: 342,888

Foreign Application Priority Data Oct. 9, 1968 Germany 1802052 Related U.S. Application Data Continuation-impart of Ser. No. 197,477, Nov. 10, 1971, abandoned, which is a continuation of Ser. No. 865,171, Oct. 9, 1969, abandoned.

US. Cl 252/3; 252/8.05 A62D 1/00 Field of Search 252/3, 8.05

[56] References Cited UNITED STATES PATENTS 2,543,672 2/1951 Saxe et a1. 252/8.05 X 3,621,917 11/1971 Rosen et a1 i 252/8.05 X

3,660,452 5/1972 Morehouse 252/3 X 3,677,347 7/1972 Rosen et al. 252/8.05 X

Primary Examiner-Stephen J. Lechert, Jr. Attorney, Agent, or Firm-Toren, McGeady and Stanger 6 Claims, N0 Drawings FIRE EXTINGUISHING FOAM CONCENTRATE CROSS REFERENCE TO PRIOR APPLICATIONS This is a continuation-in-part of application Ser. No. 197,477, filed Nov. 10, 1971, now abandoned, which in turn was a continuation of application Ser. No. 865,l7l, filed Oct. 9, 1969, and now abandoned.

FIELD OF INVENTION The invention relates to fire extinguishing foam concentrates which contain surface active substances and, if desired, water. The fire extinguishing foam concentrate of the invention is particularly suitable for use with sea water.

BACKGROUND INFORMATION AND PRIOR ART As is generally known, fires, particularly fires of fuels and propellants, are combatted by spraying foam in the form of continuous coats or coverings. Such foam blankets are also suitable for preventing the initial formation of fires.

Suitable prior art foamingagents for such purposes are prepared from protein salts, as for example from kcratins, albumins, seed flour and the like which are modified by hydrolysis and stabilized with certain preselected metal salts.

However, as is wellknown in the art, foaming agents produced from protein hydrolysates cannot successfully be used for the'fcombatting of certain types of fires. Thus, for example, such foaming agents are not suitable for fighting fuel fires or fires of polar substances as, for example, alcohol fires.

A further drawback of these known foaming agents resides in the fact that they are incompatible with dry fire extinguishing powders which are customarily used simultaneously, particularly if the powders have silicone containing surfaces. If such prior art foaming agents are used in conjunction with dry fire extinguishing powders, the foam has a tendency to collapse.

It has'also recently been suggested to employ foaming agents which are water soluble, ion-active derivatives of a fluorocarbonor a fluorosulfonic acid. Such compounds are usually applied in the form of an aqueous master solution. Concentrates of this kind have been described, for example, in German Patent 1,2l6,l 16. However, also the latter type of prior art foaming agents are not fully satisfactory. While it is true that such ion-active derivatives of fluorocarbon or fluorosulfonic acid are largely stable toward dry fire extinguishing powders, these foaming agents,-however, cannot be foamed with hard water, particularly .sea water. This, of course, limits the usefulness of the foaming agents to a considerable extent. This is so, because for combatting fires on ships, for example tankers, on the high sea, only sea water is available for preparing the foams. Accordingly, it is the primary object of the present invention to provide a fire extinguishing foam concentrate which, in addition to the beneficial properties of the prior art foaming agents, also exhibits compatibility and stability in respect to sea water and can be foamed with such water.

Concerning the prior art fluorocarbon tensides it should also be added that such tensides are extremely expensive since their manufacturing processes are exceedingly complicated. Accordingly, it is a further object of the invention to provide superior foaming agents of the indicated kind which are relatively inexpensive to manufacture and have economical advantages not obtained by the prior art agents.

Finally it should be mentioned that the prior art fluor-containing tensides do not readily form stable aqueous foams of high expansion rates.

Accordingly, it is a still further object of the present invention to provide a foaming agent or concentrate of the indicated kind which has superior expansion rate properties as compared to the prior art compounds and which forms stable, aqueous foams.

SUMMARY OF THE INVENTION In accordance with this invention it has surprisingly been found that the above objects are superiorly obtained if the fire extinguishing foam concentrate contains as active ingredient a water soluble, surface active organosilicon compound. Generally, the concentrate should contain between about 10 by weight of the active compound. The inventive concentrate, if it essentially consists of the active substance, may be used without any further additions provided the respective surface active organosilicon compound exhibits a suitable viscosity. If the inventive concentrate contains less than 100% by weight of active substance, then the remainder of the concentrate may be a suitable solvent such as, for example, water, a water miscible organic liquid, as for example ethanol, or mixtures of water and water miscible organic liquids.

The inventive concentrates are supplied in known manner to foaming devices, wherein a dense creamlike foam is produced with water. Experiments have indicated that, calculated on the amount of water used for producing the foam, advantageously 0.2 to 4% by weight of the organosilicon surface active compound should be used for producing superior fire fighting foams. The foam formed in this manner may be varied within wide limits in respect to its specific gravity. The water soluble surface active organosilicon compounds of the inventive foaming agents lend themselves for the production of highly expanding fire fighting foams.

In the event that the inventive fire fighting or extinguishing concentrate is provided in the form of an aqueous solution, then the pH of the solution should have an approximately neutral value. Preferred pH values are in the range between 7 and 9.

Water soluble polymers or polymer mixtures can be successfully employed in accordance with this invention which have the general formula I RO- i0 Si0- R l wherein:

R is alkyl, preferably lower alkyl of l4 carbon atoms. or (CH Si; a O 5; b l 3;

R is alkyl or aryl, preferably CH or (CH SiO;

R is divalent hydrocarbon or O, preferably X is a hydrophilating group which may be anionic, cationic or nonionogenic; X is preferably O,,SO;,

R-O- i-O- R' Ho- Si- H wherein m a a.

This is important because these contaminants have a defoaming action, particularly if siloxanols are involved. For this reason compounds of formula 1 could not successfully be used in the foam concentrates if they were to contain these contaminants.

A particularly preferred subgeneric group of compounds of the general formula 1 are those represented by the formula 11:

Si-O- u In this formula:

R (CH Si; up to 50 mole percent within a polymer mixture may be replaced by alkyl of [-4 carbon atoms; preferred are compounds in which 5-25 mole percent of the (CH Si groups are replaced by alkyl;

m ]3, preferably l1.3;

p q r l-20, preferably 3-10.

Compounds corresponding to formula 11 can be readily prepared according to the teachings of German patent 1,179,937 if is used as base. In doing so, products of formula 11 are mostly obtained wherein a predetermined proportion of the R -groups are not (CH;,) Si but rather alkyl of 1-4 carbon atoms. As previously stated, such products, wherein a portion of R is constituted by alkyl of l-4 carbon atoms are particularly suitable for the inventive purposes.

Compounds of formula 1 wherein R -CH- CH and X -SO Me can be prepared according to the procedure disclosed in German Auslegeschrift 1,206,160 by reacting the corresponding vinyl-group containing siloxanes with MeHSO Other compounds which may be used for the purposes of this invention are generally represented by the following formula 111 wherein:

R alkoxy of 1-4 carbon atoms, (CH;,) SiO or alkyl of l-4 carbon atoms; alkoxy is preferred; 5 alkyl, hydrogen or (CH CH O), -,H, thus, for example 1-ll IR,-, NH(C H HN(CH CH OH) or HN(iC H and S 2-5. Compounds of formula [11 may be prepared in a manner known per se as follows One mole of siloxanols of the formula is mixed with amines of the formula NR (2 or 4 moles and 5-20% of excess). The mixture thus obtained and 2 moles of organosilicon sulfates of the formula wherein R C1 or alkyl of l-4 carbon atoms, are then synchronously added to an inert solvent in dropwise manner.

The organosilicon sulfates referred to may be prepared pursuant to the procedure disclosed in German patent 1,157,789.

The products thus obtained and if R C1 are subsequently reacted with compounds of the formula R OH, for example, C H OH or (CH SiOH, are separated from the solvent and, if necessary, filtered. If R Cl, then 4 moles of the amines of the formula NR,-, are required plus an excess of 520%. By contrast, if R alkyl, 2 moles of the amines of formula NR5 plus an excess of 5-20% are sufficient.

1t should be added that other siloxanes than those of formulas I, I1 and 111 can be successfully employed within the scope of this invention. Thus, compounds of the following formula IV are very suitable wherein:

m, R and R have the meaning defined in formula 11; R divalent hydrocarbon or 0 CIHCH2O CH1 wherein can be prepared in known manner by reacting polyethers of the formula R(OCHJIHgMOiH-CHQDH with corresponding siloxanes which latter contain SiH, SiCl or SiO-alkyl groups. The interconnection between the polyethers and the siloxanes then takes place under splitting off H HC] or alkanol.

A still further group of siloxanes which is useful for the inventive purposes is symbolized by the formula V:

In this formula:

n, R and R have the same meaning as in formula IV; S 25; and R alkyl of 1-4 carbon atoms, preferably CH Formula V compounds may be prepared in the same manner as the formula IV compounds, to wit, by hydrosilatingly forming an adduct of siloxanes of the formula and polyethers with olefinic terminal groups or by re acting the siloxanes with polyethers of the formula under splitting off of H The last-mentioned polyethers may also be reacted in esterifying or reesterifying manner with siloxanes 0f the formula:

iv CH, l

in which event HCl or alkanols are split off.

A still further siloxane system which has been demonstrated to be suitable for the inventive foam concentrates is represented by the formula VI:

RO iO R V1 RNR,,

wherein m, R and R are as defined in formula II; R is divalent hydrocarbon, preferably CH or 2):i R hydrogen or alkyl; Z is a halogen anion, except fluoride and preferably chloride.

However, Z need not be the anion of a halogen acid but can symbolize the anion of any other acid. Thus, Z may stand for acetate, formate, sulfate/2 etc.

Compounds of formula VI may be prepared as follows:

compounds of the formula are reacted with amines or compounds of the formula are reacted with acid of the formula ZH.

Such reactions are known in the art and have been disclosed in German Auslegeschrift 1,128,985 and by H. Maki, M. Komatsu and S. Komori, Kogyo Kagaku Zasski (1967) 1771-4 (CA. 68 (1968) 3865).

wherein R and S have the meaning as in formula V; and R, R and Z are defined as in formula VI.

Formula Vll compounds are produced by reacting compounds of the formula:

ity towards hard water, as for example, sea water. In order to test this characteristic, the so-called impact foam test was employed. A detailed description of the impact foam test is contained, for example, in the book by E. Manegold: Schaum, Strassenbau, Chemie and Technik-Verlagsgesellschaft m.b.H., Heidelberg, l953, pages 97 and 98. In performing the test, a measuring cylinder with a diameter of 5.4 cm was used. The disc, used for the impact foam test, had a diameter of cm and contained 87 holes with a diameter of 1 mm for each hole. The material to be foamed was filled into the measuring cylinder to a level of 3 cm and was thereafter foamed by moving the disc up and down for times. The results which were obtained are tabulated in the following Table I.

TABLE I lmpact Foam Test Distilled Water Sea Water Concentrate Employed HVT Foam Height HVT Foam Height Concentration in mm in mm Concentrate a) corresponding to formula ll. m l; R (CH MSL 8 mole percent of the (CH;,);,Si groups l7! 7'16" 270 2'56" 140 are replaced by C H groups, R CH pq r= 2.4;1pq r=7.2 27: 7'53" 31() 3'26" 230 Fluorocarhonconcentrate h) 5% 5'26 l5() 2 50 as commercially available 3% 2'4l" l3(l no foam no foam Concentrate e) (T flu Si I 1% 4'29" I80 5'40" 260 l 1l CH CH-1 )zlOCH- |CH ;;OCH

1 3 ii 2% 5'3l" 250 6'36" 210 alri Ha H3 H3 The abbreviation HVT in the Table stands for half R" O i O i Rx value time and indicates the time period which passed i until an amount of liquid had been reformed which R al0gcn H S "Halogcn corresponded to one half of the original amount. The

with amines. In the alternative, compounds of the formula height of the foam was measured in millimeter.

Table I clearly indicates that the inventive concentrate can be readily foamed with sea water and that the concentrate results in foams of larger expansion rates. The term expansion rate indicates the ratio of the foam volume to the volume of the original liquid. For comparison purposes, a fluorocarbontenside, as it is commercially available and as it is used for fire extinguishing foam concentrates, was tested as seen in Table 1 Fire extinguishing tests were also carried out with the inventive fire extinguishing foam concentrates and with prior art concentrates. As combustible materials, normal gasoline, super gasoline and n-butanol were used. cm of these liquids were in each case fed to a pot ofa diameter of 14.5 cm. The liquids were then ignited and after a burning time of 2 minutes the extinguishing or fire combatting procedure was initiated.

The foam was produced according to the impact foam method with ordinary tap water and was sprayed in measured amounts onto the burning surfaces. The results are tabulated in the following Tables:

TABLE 11 a 1 Fire Extinguishing Tests Employed Ex- Normal Gasoline Concentrate Concentration pan- Extinguishing Time Amount of Concentrate sion with different for Extinction in Amounts of Foam 15 seconds Concentrate a) corresponding to formula 11 2% 1:9 210 ml 27" m= l: 320ml= l6" 075g R (CH MSi, 8 mole-7r of the (CH:.);,Si 520 ml 18" groups are replaced by CH; groups 1% 1:8 681) ml 17" 1.0 g 800 ml= 15" 570 ml 19" P q r 015 1:7 68(1ml=13" 0.48 g 2 p q r 7 2 270 ml 15" Fluorocarhon h) 5% 1:4 320 ml 13" 345 g Commercially available 371 1:2 no foam Concentrate c) 1 ula i 2% 1:7 680 ml 16" v: 57()ml=18" 2.01 g

Cll i(O HCH,] -(OCH CH M OCH 570 ml 25" CH; 1% 1:6 680ml=13" 1.1 g ii ll)il TABLE 11 a 2 Fire Extinguishing Tests Em- Ex- Normal Gasoline ployed Concentrate Conccnpan- Extinguishing Time Amount of Concentrate tration sion with different for Extinction in Amounts of Foam 15 seconds 461) ml 19" Concentrate d) 2% 1:5 571) ml 15" 2.35 g

iC;,H;-O iO iO iOi-C;,H

( 2)Il a 2)-'l 0:. O (cm- NH Q 0:, 6 c nmun 400 ml 18" 1.37 g

1% 1:4 S70ml= 14" TABLE II b 1 Fire Extinguishing Tests Super Gasoline Concentrate Employed Ex- Extinguishing Time Amount of Concentrate Concentration panwith different for Extinction in sion Amounts of Foam 15 seconds Concentrate a) corresponding to formula ll 220 ml 47" m l; R' (CHmSi. X mole-Ir of the 2% 1:9 320 ml 21" 093 g aln i-groupsi are replaced by C 11,; 375 ml 14" groups: R 570 m1 18" 17: 1:8 730 ml 17" H) g pqr=2.4 8()0ml=15" 571) ml 20'' hp q r= 7.2 0.57: 1:7 730m1= 16" (1152 g 210 ml 21" Fluorocarhoneoneentrate h) 5% 1:4 320 ml 17" 4.4 g as commercially available 371 1:2 no foam Concentrate e) 1 ula (181) ml 17" 640 ml 18" 2.2 g i Y 2% 1:7 500 ml not extinguished TABLE II b 2 Fire Extinguishing Tcsts Super Gasoline Concentrate Employed Ex- Extinguishing Time Amount of Concentrate Concentration panwith different for Extinction in sion Amounts of Foam 15 seconds Concentrate d) a CH H 460 ml 19" 271 I5 570 ml 16" 2 ll g i( ,H;--()-.i0 iO iOiC;,H; 680 ml 15" ula a :t zla 570 ml l6" l7: I4 680 ml 14" 1.58 g

TABLE II c 1 Fire Extinguishing Tests n-Butanol Concentrate Employed Ex Extinguishing Time Amount of Concentrate Concentration panwith different for Extinction in sion Amounts of Foam 15 seconds Concentrate a) corresponding to 2% It) ZlO ml 4" 0.45 g formula II 190 ml 16" m l;

R (CHM- SL 8 mole-71 of the 1% 1:8 340 ml 12" 0.38 g

(CH l si-groups are replaced by 450 ml 7'' (1H; groups;

R CH,; 0457! I17 390 ml 15" 028 g 45()ml=8" E p q r 7,2

ZlU ml 14" Fluorocarhonconccntrate h) 5'7: l:4 320 ml 5" 2.7 g as commercially available 380 ml 4" 371 1:2 no foam Concentrate c) No corresponding value H 460 ml 5" could be extrapolated. The

340 ml 6" amount of concentrate for i 271 1:7 270 ml an extinction time of 6 not extinguished seconds is calculated to be 0.99 g

CH;, l-(0 HCH2l2 2 2 |a a 300 ml l4" H. 1% m 340 ml =13" 0.48 g

TABLE II c 2 Fire Extinguishing Tests Concentrate Employed Ex- Extinguishing Time Amount of Concentrate Concentration panwith different for Extinction in sion Amounts of Foam l5 seconds Concentrate d) 2% 1:5 270 ml 13" [.03 g

340 ml 5" H a iC,,H O iO ii-O- i o i c.,|-|

( H2) HI! {I 2):!

1% 1:4 270 ml 14" 0.64 g 340 ml 5" 0.9 rc2 o3NH 0.. C2H5)=.N

Tables Ila to He demonstrate the superior activity and The expansion rates are in the inventive substances 1 effect of the inventive substances. ln interpreting the t0 9 while in the comparison prior art substances the Tables, it should be observed that the beneficial charrate is only 1 to 4. Comparative extinction periods at acterrstics of the respective substance should be evaluhigher expansion rates means, of course, increased ated more favorable especially if the substance is used economy of the concentrates. In order to consider all in smaller concentrations. Further the expansion rates these factors, the Tables contain a column in which the should be considered in the results. amount of concentrates is indicated which was necessary for extinguishing the fire within 15 seconds with R2 the comparison test. The value for the 15 second extin- 1 l guishing time, was extrapolated if not measured by (CH2CH2O)|IH tests.

Comparison tests were also carried out with a substance of formula 11 and those disclosed in Example 2 (cH'lcHflolrH of the US. Busse Pat. No. 2,506,062, in Example 2 of m the US. Busse Pat. No. 2,514,310, in Example 1 of the US. Busse Pat. No. 2,529,211, and in Example 43 of Whemln the US. Jackovitz Pat. No. 3,422,021. The respective foams were for this purpose prepared as described in R1 is (cflxhsi; connection with Table l. The test results are tabulated in Table Ill. R is CH; or (Cl-1 );,SiO;

TABLE III Foam Concentration HVT Expansion Extinguishing time Concentrate in 7c in minutes Rate required for Regular Super n-hutanol gasoline gasoline As disclosed in 2 5 l 7.7 no exno exno exting- Example 2 of US. tinguishing tinguishing uishing Patent 2,506,062 effect effect effect to Busse As disclosed in 2 l2 1 33 no exno exno ex- Example 2 of US. tinguishing tinguishing tinguishing Patent 1.514.310 effect effect effect to Busse As disclosed in 1.2 5.5 l 4.8 no exno exno ex- Example 1 of [1.5. tinguishing tinguishing tinguishing Patent 2,529.21 I effect effect effect to Busse As disclosed in L64 l5.() 1 10.2 16 seconds 10 seconds no ex Example 43 of US. tinguishing Patent 3,422.0l 1 effect to Jackovit/v Product of formula ll 2.() 8.0 l 9 12 seconds 10 seconds 3 seconds wherein m l; 1 7.2 R ala 8 mole-'71 of (CH Sigroups are replaced by C- .H groups-R CH The terms HVT and expansion rate as appearing in m 1 3;

Table 111 have the same meaning as explained in con- 40 p, q, r 7 and nection with Table l. The fire extinguishing tests were r performed as previously described in connection with p q Tables ll. 60 grams of foam were used in each test and 2 Th improvement of l i 1, h i h come. the burning substances were inherently difficult to ex- "ate Contains water v tinguish. Table 111 clearly demonstrates that the Slll- The improvement of Claim 1, wherein within a eone-tenside of formula 11 which was used as an example, exhibited significantly better fire fighting characi g g i i pcrtcem oflclmgsl are teristics than the foams of Bussc and Jackovitz. lt folrep ace a y 0 car a lows that foam producing substances, although exhibit- Thc Improvement of claim 1, Whel'em ing surface tension lowering characteristics, are not and P 1+ r: necessarily suitable for fire fighting. It also follows that 5. The improvement as claimed in claim 1, wherein the inventive surface active compounds are superior to the concentrate essentially consists of at least 10 per those of the comparison products. cent of said compound, the remainder being a solvent,

What is claimed is: said solvent being water and/or a water miscible 0r- 1. In a fire extinguishing foam concentrate, the imganic liquid. I provement which comprises that its active ingredient is 6. The improvement as claimed in claim 1, wherein a water-soluble, surface active organosilicon comthe concentrate is in the form of an aqueous solution pound, said compound constituting at least 10 percent having a pH value of about between 7 and 9. of said concentrate and having the formula =l 

1. IN A FIRE EXTINGUISHING FOAM CONCENTRATE, THE IMPROVEMENT WHICH COMPRISES THAT ITS ACTIVE INGREDIENT IS A WATER-SOLUBLE, SURFACE ACTIVE ORGANOSILICON COMPOUND, SAID COMPOUND CONSTITUTING AT LEAST 10 PERCENT OF SAID CONCENTRATE AND HAVING THE FORMULA
 2. The improvement of claim 1, wherein the concentrate contains water.
 3. The improvement of claim 1, wherein within a polymer mixture up to 50 mole percent of (CH3)3Si are replaced by alkyl of 1-4 carbon atoms.
 4. The improvement of claim 1, wherein m 1-1.3 and p + q + r 3-10.
 5. The improvement as claimed in claim 1, wherein the concentrate essentially consists of at least 10 per cent of said compound, the remainder being a solvent, said solvent being water and/or a water miscible organic liquid.
 6. The improvement as claimed in claim 1, wherein the concentrate is in the form of an aqueous solution having a pH value of about between 7 and
 9. 